Patents by Inventor James Mac Freitag

James Mac Freitag has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20190279667
    Abstract: A spin transfer torque (STT) device has a free ferromagnetic layer that includes a Heusler alloy layer and a template layer beneath and in contact with the Heusler alloy layer. The template layer may be a ferromagnetic alloy comprising one or more of Co, Ni and Fe and the element X, where X is selected from one or more of Ta, B, Hf, Zr, W, Nb and Mo. A CoFe nanolayer may be formed below and in contact with the template layer. The STT device may be a spin-torque oscillator (STO), like a STO incorporated into the write head of a magnetic recording disk drive. The STT device may also be a STT in-plane or perpendicular magnetic tunnel junction (MTJ) cell for magnetic random access memory (MRAM). The template layer reduces the critical current density of the STT device.
    Type: Application
    Filed: May 10, 2018
    Publication date: September 12, 2019
    Applicant: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: JAMES MAC FREITAG, ZHENG GAO, MASAHIKO HASHIMOTO, SANGMUN OH, HUA AI ZENG
  • Publication number: 20190259412
    Abstract: Spin transfer torque (STT) devices with multilayer seed layers that can be used in magnetic recording and memory are provided. One such STT device includes a substrate, and a stack of layers formed on the substrate, where the stack includes a first seed layer directly on the substrate and including Cr, a second seed layer on the first seed layer and including Ta, a ferromagnetic free layer on the second seed layer; a ferromagnetic polarizing layer, and a nonmagnetic spacer layer between the free layer and the polarizing layer. One such method includes fabricating the STT device.
    Type: Application
    Filed: February 15, 2019
    Publication date: August 22, 2019
    Inventors: Zheng GAO, Masahiko HASHIMOTO, Susumu OKAMURA, James Mac FREITAG
  • Patent number: 10121500
    Abstract: In one embodiment, a system includes a sensor, the sensor having a free layer, a ferromagnetic spin sink layer spaced from the free layer, the spin sink layer being operative to reduce a spin-induced damping in the free layer during operation of the sensor, and a nonmagnetic spacer layer positioned between the free layer and the spin sink layer, the spacer layer having a long spin-diffusion length.
    Type: Grant
    Filed: June 12, 2018
    Date of Patent: November 6, 2018
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Zheng Gao, James Mac Freitag
  • Publication number: 20180294003
    Abstract: In one embodiment, a system includes a sensor, the sensor having a free layer, a ferromagnetic spin sink layer spaced from the free layer, the spin sink layer being operative to reduce a spin-induced damping in the free layer during operation of the sensor, and a nonmagnetic spacer layer positioned between the free layer and the spin sink layer, the spacer layer having a long spin-diffusion length.
    Type: Application
    Filed: June 12, 2018
    Publication date: October 11, 2018
    Inventors: ZHENG GAO, JAMES MAC FREITAG
  • Patent number: 10026426
    Abstract: In one embodiment, a system includes a sensor, the sensor having a free layer, a ferromagnetic spin sink layer spaced from the free layer, the spin sink layer being operative to reduce a spin-induced damping in the free layer during operation of the sensor, and a nonmagnetic spacer layer positioned between the free layer and the spin sink layer, the spacer layer having a long spin-diffusion length.
    Type: Grant
    Filed: January 31, 2018
    Date of Patent: July 17, 2018
    Assignee: Western Digital Technologies, Inc.
    Inventors: Zheng Gao, James Mac Freitag
  • Publication number: 20180151193
    Abstract: In one embodiment, a system includes a sensor, the sensor having a free layer, a ferromagnetic spin sink layer spaced from the free layer, the spin sink layer being operative to reduce a spin-induced damping in the free layer during operation of the sensor, and a nonmagnetic spacer layer positioned between the free layer and the spin sink layer, the spacer layer having a long spin-diffusion length.
    Type: Application
    Filed: January 31, 2018
    Publication date: May 31, 2018
    Inventors: ZHENG GAO, JAMES MAC FREITAG
  • Patent number: 9911439
    Abstract: In one embodiment, a system includes a sensor, the sensor having a free layer, a ferromagnetic spin sink layer spaced from the free layer, the spin sink layer being operative to reduce a spin-induced damping in the free layer during operation of the sensor, and a nonmagnetic spacer layer positioned between the free layer and the spin sink layer, the spacer layer having a long spin-diffusion length.
    Type: Grant
    Filed: August 10, 2017
    Date of Patent: March 6, 2018
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Zheng Gao, James Mac Freitag
  • Publication number: 20170372730
    Abstract: In one embodiment, a system includes a sensor, the sensor having a free layer, a ferromagnetic spin sink layer spaced from the free layer, the spin sink layer being operative to reduce a spin-induced damping in the free layer during operation of the sensor, and a nonmagnetic spacer layer positioned between the free layer and the spin sink layer, the spacer layer having a long spin-diffusion length.
    Type: Application
    Filed: August 10, 2017
    Publication date: December 28, 2017
    Inventors: ZHENG GAO, JAMES Mac FREITAG
  • Patent number: 9734850
    Abstract: In one embodiment, a system includes a sensor, the sensor having a free layer, a ferromagnetic spin sink layer spaced from the free layer, the spin sink layer being operative to reduce a spin-induced damping in the free layer during operation of the sensor, and a nonmagnetic spacer layer positioned between the free layer and the spin sink layer, the spacer layer having a long spin-diffusion length.
    Type: Grant
    Filed: June 28, 2016
    Date of Patent: August 15, 2017
    Assignee: Western Digital Technologies, Inc.
    Inventors: Zheng Gao, James Mac Freitag
  • Patent number: 9177588
    Abstract: The embodiments of the present invention relate to a method for forming a magnetic read head with pinned layers extending to the ABS of the read head and magnetically coupled with an antiferromagnetic layer that is recessed in relation to the ABS of the read head. Portions of the antiferromagnetic layer and a magnetic layer that are extending to the ABS are removed, exposing a shield. A shielding material is formed on the exposed shield and a seed layer is formed on the shield and on or over a portion of the remaining antiferromagnetic layer. A pinned layer structure is formed on the seed layer and the magnetic layer.
    Type: Grant
    Filed: January 17, 2014
    Date of Patent: November 3, 2015
    Assignee: HGST NETHERLANDS B.V.
    Inventors: James Mac Freitag, Ying Hong, Cherngye Hwang, Stefan Maat, Masaya Nishioka, David John Seagle, Hicham Moulay Sougrati, Shuxia Wang, Yi Zheng, Honglin Zhu
  • Publication number: 20150248907
    Abstract: The embodiments disclosed generally relate to a magnetic read head having a recessed antiferromagnetic layer and a recessed pinned magnetic layer. The recessed pinned magnetic layer is only partially recessed from the MFS, but the recess amount is the same amount as the antiferromagnetic layer. The recess is between about 50 nm and about 200 nm. Processing the pinned magnetic layer and the antiferromagnetic layer and its seed layers at an oblique angle results in an increase in the anisotropy field.
    Type: Application
    Filed: February 28, 2014
    Publication date: September 3, 2015
    Applicant: HGST NETHERLANDS B.V.
    Inventors: James Mac FREITAG, Zheng GAO, Simon Huangchung LIAO, Suping SONG
  • Patent number: 9099124
    Abstract: A tunneling magnetoresistance (TMR) device, like a magnetic recording disk drive read head, has a nitrogen-containing layer between the MgO barrier layer and the free and/or reference ferromagnetic layers that contain boron. In one embodiment the free ferromagnetic layer includes a boron-containing layer and a trilayer nanolayer structure between the MgO barrier layer and the boron-containing layer. The trilayer nanolayer structure includes a thin Co, Fe or CoFe first nanolayer in contact with the MgO layer, a thin FeN or CoFeN second nanolayer on the first nanolayer and a thin Co, Fe or CoFe third nanolayer on the FeN or CoFeN nanolayer between the FeN or CoFeN nanolayer and the boron-containing layer. If the reference ferromagnetic layer also includes a boron-containing layer then a similar trilayer nanolayer structure may be located between the boron-containing layer and the MgO barrier layer.
    Type: Grant
    Filed: September 28, 2014
    Date of Patent: August 4, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: James Mac Freitag, Zheng Gao
  • Patent number: 9099120
    Abstract: The embodiments generally relate to a read head in a magnetic recording head. The read head utilizes a sensor structure having a pinned magnetic structure with a magnetic field, a barrier layer disposed on top of the pinned magnetic structure, a free layer disposed on top of the barrier layer, and an interlayer coupling field canceling layer disposed on top of the free layer. The interlayer coupling field canceling layer has a cancelling magnetic field pinned anti-parallel the magnetic field of the pinned magnetic structure.
    Type: Grant
    Filed: April 9, 2014
    Date of Patent: August 4, 2015
    Assignee: HGST NETHERLANDS, B.V.
    Inventors: James Mac Freitag, Zheng Gao
  • Publication number: 20150206550
    Abstract: The embodiments of the present invention relate to a method for forming a magnetic read head with pinned layers extending to the ABS of the read head and magnetically coupled with an antiferromagnetic layer that is recessed in relation to the ABS of the read head. Portions of the antiferromagnetic layer and a magnetic layer that are extending to the ABS are removed, exposing a shield. A shielding material is formed on the exposed shield and a seed layer is formed on the shield and on or over a portion of the remaining antiferromagnetic layer. A pinned layer structure is formed on the seed layer and the magnetic layer.
    Type: Application
    Filed: January 17, 2014
    Publication date: July 23, 2015
    Applicant: HGST Netherlands B.V.
    Inventors: James Mac FREITAG, Ying HONG, Cherngye HWANG, Stefan MAAT, Masaya NISHIOKA, David John SEAGLE, Hicham Moulay SOUGRATI, Shuxia WANG, Yi ZHENG, Honglin ZHU
  • Patent number: 9030785
    Abstract: The embodiments of the present invention relate to a magnetic read head with pinned layers extending to the ABS of the read head and in contact with an antiferromagnetic layer that is recessed in relation to the ABS of the read head. The recessed antiferromagnetic layer may be disposed above or below the pinned layer structure and provides a pinning field to prevent amplitude flipping in head operation. In these embodiments of the present invention, the read gap of the sensor, that is the distance between the highly permeable, magnetically soft upper and lower shield layers at the ABS, is reduced by the thickness of the antiferromagnetic layer.
    Type: Grant
    Filed: June 21, 2013
    Date of Patent: May 12, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: James Mac Freitag, Zheng Gao
  • Patent number: 9001473
    Abstract: The embodiments disclosed generally relate to a read head in a magnetic recording head. The read head utilizes a sensor structure having: a pinned magnetic structure recessed from a media facing surface; and a reader gap structure. The reader gap structure has a spacer layer recessed from the media facing surface and disposed on top of the pinned magnetic structure, a recessed first free layer partially recessed from the media facing surface and disposed on top of the barrier layer, a second free layer extending to the media facing surface an disposed on top of the barrier layer, and a cap layer extending to the media facing surface disposed atop the second free layer. The pinned magnetic structure, the spacer, and the first free layer have a common face which is on an angle relative to the media facing surface.
    Type: Grant
    Filed: March 21, 2014
    Date of Patent: April 7, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: Zheng Gao, James Mac Freitag, Kuok San Ho, Ching Hwa Tsang, Kochan Ju
  • Publication number: 20150062759
    Abstract: Embodiments of the present invention generally relate to a magnetic head having a sensor structure comprising a pinned layer, a spacer layer, a free layer and a capping structure. The free layer has a topmost layer comprising CoB and the capping structure comprises an X layer, where X is an element such as Hf, Zr, Ti, V, Nb, or Ta.
    Type: Application
    Filed: August 28, 2013
    Publication date: March 5, 2015
    Inventors: Chando PARK, Zheng GAO, Sangmun OH, Susumu OKAMURA, James Mac FREITAG
  • Patent number: 8958180
    Abstract: Embodiments of the present invention generally relate to a magnetic head having a sensor structure comprising a pinned layer, a spacer layer, a free layer and a capping structure. The free layer has a topmost layer comprising CoB and the capping structure comprises an X layer, where X is an element such as Hf, Zr, Ti, V, Nb, or Ta.
    Type: Grant
    Filed: August 28, 2013
    Date of Patent: February 17, 2015
    Assignee: HGST Netherlands, B.V.
    Inventors: Chando Park, Zheng Gao, Sangmun Oh, Susumu Okamura, James Mac Freitag
  • Publication number: 20140377589
    Abstract: The embodiments of the present invention relate to a magnetic read head with pinned layers extending to the ABS of the read head and in contact with an antiferromagnetic layer that is recessed in relation to the ABS of the read head. The recessed antiferromagnetic layer may be disposed above or below the pinned layer structure and provides a pinning field to prevent amplitude flipping in head operation. In these embodiments of the present invention, the read gap of the sensor, that is the distance between the highly permeable, magnetically soft upper and lower shield layers at the ABS, is reduced by the thickness of the antiferromagnetic layer.
    Type: Application
    Filed: June 21, 2013
    Publication date: December 25, 2014
    Applicant: HGST Netherlands B.V.
    Inventors: James Mac FREITAG, Zheng GAO
  • Patent number: 8266785
    Abstract: A method for manufacturing a magnetoresistive sensor having improved pinned layer stability at small track widths. The method includes providing a substrate, and depositing a plurality of sensor layers. A layer of material that is resistant to removal by chemical mechanical polishing (CMP stop layer) and an antireflective coating layer are deposited. A photoresist mask is formed on the antireflective layer, and a reactive ion etch (RIE) is performed to remove portions of the ion mill resistant mask that are not covered by the photoresist mask, the RIE being performed in a plasma chamber having a platen, the performing the RIE further comprising applying a platen power of at least 70 W. An ion milling is performed to remove a portion of the sensor layers, the ion milling being terminating before all of the sensor materials have been removed.
    Type: Grant
    Filed: November 12, 2007
    Date of Patent: September 18, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Wipul Pemsiri Jayasekara, Mustafa Michael Pinarbasi